// Copyright 2006-2012 Brendan Burns
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#include <unistd.h>
#include <stdio.h>
#include <errno.h>

int write_serial(int fd, char *msg, int count) {
  int wr = 0;
  do {
    int ret = write(fd, msg+wr, count-wr);
    if (ret <= 0) {
      perror("serial write: ");
      return ret;
    }
    wr += ret;
  } while (wr < count);
  //tcdrain(fd);
  //fsync(fd);
  return 0;
}

int read_serial(int fd, char *msg, int n) {
  int rd=0;
  
  while (rd != n) {
    int r = read(fd, msg+rd, n-rd);
    if (r == 0) {
      printf("EOF: %d chars of %d read.\n", rd, n);
      break;
    }
    else if (r < 0) {
      perror("read serial: ");
      break;
    }
    else {
      rd += r;
    }
  }
  return rd;
}
